The invention relates to substrate polishing techniques, including chemical mechanical polishing (CMP).
Chemical mechanical polishing is a process by which a substrate surface is smoothed (planarized) to a uniform level by a polishing pad and an abrasive slurry. A substrate to be polished is usually mounted on a rotatable carrier head and pressed against a moving polishing pad. The polishing pad typically consists of an abrasive sheet. An abrasive chemical solution (slurry) may be introduced onto the polishing pad to assist in the polishing process. Typically, a rinse arm supplies de-ionized water or other rinse fluid to the polishing pad to remove coagulated slurry and other material from the polishing pad surface.